The Jingweon Mafia originated in South Korea but, during the 1970's it established a foothold in Tokyo's underworld, where it eventually became enemies with that city's reigning local crime syndicate, the Tojo Clan.
The mafia itself consists of well-trained operatives, trained in hand-to-hand combat and weapon usage. Their primary form of attire consists of dark clothing, frequently with combat boots and military camo.
It's famous for their "death before dishonor" creed, in which the mafia's operatives are obliged to commit suicide rather than living in dishonor for failing to carry their missions. To do this, Jingweon operatives usually wear a ring which contains a poisonous powder hidden inside its jewel crown. Additionally, the murder of any member of the Jingweon must be paid back with the murder of their killer, lest the entire organization be shamed.
During the late 1970's, the Jingweon and the Tojo had gotten into a years-long war for control over the Tokyo underworld and, by 1980, the Tojo Clan was losing. However, Dojima Family patriarch Sohei Dojima got intel that the Jingweon's leadership would be attending a party in the warehouse behind one of their clubs on Christmas Day in 1980. Seizing the opportunity, Dojima dispatched his two lieutenants, Shintaro Kazama and Futoshi Shimano, to take out the Jingweon's leaders.
While Shimano carried out the massacre with passion, Kazama tried to warn the Jingweon leader to flee the town with his men and never return in exchange for their lives. Nearby, a then-12-year-old Kazuma Kiryu, Kazama's adopted son who had followed him to the warehouse party, was watching and, mistakenly believing that the Jingweon Boss was trying to kill Kazama, he intervened. This provoked the boss into attacking Kiryu, forcing Kazama to shoot and kill him, signaling Shimano and the rest of the Dojima assassins to spring into action and begin massacring the rest of the Jingweon leaders present.
36 members of the Jingweon were killed in what came to be known as the "Kamurocho Christmas Massacre" or the "Jingweon Massacre", including the entirety of the group's leaders and many of their bodyguards. Of those present at the massacre, only five Jingweon survived: three young bodyguards whom Kazama took pity on and helped escape, called Daejin Kim, Yeongmin Ji and Hoejong Park; and the boss' wife, Suyeon Jung, and her young child, who were helped by the first police officer on the scene, Jiro Kawara.
After the massacre, the Jingweon were thought to be wiped out in Japan. However, Kim and Ji went into hiding, promising to one day get into contact with the Jingweon's mainland organization to plot their revenge against the Tojo Clan. Said plan came to be 26 years after the Christmas Massacre, in 2006.
By that year, Kim (living under the alias of "Yukio Terada") had infiltrated the Tojo Clan and risen to become it's fifth chairman, while Ji (under the name "Wataru Kurahashi") had become the Tokyo Metropolitan Police's superintendent for the Foreign Affairs Division. Kim faked his own murder by Omi Alliance assassins in order to spark a war between the Tojo and the Omi, in the hopes that it would finally destroy the very weakened Tojo Clan. In order to aid that destruction, the Jingweon also prepared a multitude of bombs that they intended to place all over Tojo Clan businesses in Tokyo and detonate them when the Omi Alliance made their move against them.
Unfortunately for the Jingweon, Kiryu and his allies, Kaoru Sayama, Makoto Date and Jiro Kawara discovered the Jingweon's return and began to uncover their schemes. Ji was eventually discovered as an infiltrator and killed by Sayama during a confrontation in Millenium Tower. Additionally, the bombs were also discovered and defused by Goro Majima and his construction company before they could be detonated.
When the Omi Alliance invasion failed to eradicate the Tojo, Kim took direct action and decided to murder Kiryu, Sayama and the Tojo's leadership personally. He revealed his ruse to Kiryu by showing up after his fight with Ryuji Goda atop the Kamurocho Hills construction site and, along with a platoon of Jingweon assassins, tried to kill him. Regardless, Kiryu and Sayama managed to defeat him and his forces. Kim would soon after be killed by Ryo Takashima, the chief of Omi headquarters, who had been acting as his informant but who decided to betray him in order to take power for himself.
By 2016, the Jingweon Mafia has returned to Japan and is making a new attempt to establish itself in the country, now led by a charismatic, young officer called Joon-gi Han. Under Han's leadership, this new Japanese chapter of the Jingweon have stepped back from their fanatical adherence to the iron creed and are instead more preoccupied with turning into a successful criminal enterprise. Regardless, some of the older members of the group still harbor resentment towards Kazuma Kiryu for his role in their humiliating defeat ten years prior.
The Jingweon manage to establish themselves in Tokyo once again by doing mercenary work for the CEO of Iwami Shipbuilding and son of Yomei Alliance Chairman Heizo Iwami, Tsuneo Iwami, who is plotting to overthrow his father and take over both Hiroshima and later Tokyo. Using the money they secured through their work for Tsuneo, they managed to buy several businesses across Kamurocho, including the famous host club, Stardust, which they turned into a male striptease club.
One of the jobs that the Jingweon carries out for Tsuneo is a hit on Big Lo and Jimmy Lo, the leader and the heir of the Saio Triad; a Chinese criminal syndicate that impedes Tsuneo's control over Tokyo. However, the Jingweon's attempt on the Lo's is only partially successful, as Jimmy is killed but his father avoids execution. The Jingweon would try to assassinate Lo multiple times in the ensuing months, but they were unable to track him down, as he constantly kept on the move.
However, in March of 2016, a new opportunity arose for the Jingweon to kill Lo: A host working for Stardust called Shu Tatsukawa turned out to be a former member of the Saio who'd decided to abandon them after he'd failed a job. Tatsukawa told Joon-gi Han that Big lo had a second son, Yuta Usami, who was living in Hiroshima and was completely unaware that he was now the heir to the Saio. This son of Lo had recently unknowingly fathered a baby with Haruka Sawamura. Tatsukawa proposed that he and the Jingweon kidnap Haruka and her child and then use them to blackmail Yuta into using his blood link to Lo to get a meeting with him and then assassinate him. Han agreed to this scheme, but the plan went awry, as Haruka eventually caught onto Tatsukawa's true intentions after meeting with him and fled. While trying to capture her, Tatsukawa ended up accidentally running her over with his car, leaving her in a coma.
A couple weeks later, Kazuma Kiryu, who'd taken custody of Haruka's baby, Haruto, came to Kamurocho with Yuta and Tsuyoshi Nagumo to search for Tatsukawa, believing him to be the kid's father. Kiryu and his friends would end up meeting with Joon-gi Han who; in an attempt to appease the elder Jingweon members who still hated Kiryu, challenged the former yakuza to a duel in Stardust's underground boxing ring, agreeing to give Kiryu Tatsukawa's location if the former yakuza beat him in a fight. Despite his efforts, Han ended up defeated and gave Kiryu Tatsukawa's home address.
Later on, Tsuneo would pay the Jingweon to travel to Hiroshima and attempt to kidnap Haruto once more and then force Yuta to kill Lo. Joon-gi would personally lead several dozen of his men on this mission and they wound up being initially successful, as they managed to take Haruto captive. However, as they fled from Hiroshima via boat, they were driven to hiding in a cargo-holding barge island by fishermen and coast guard boats friendly to Kiryu's allies, the Hirose Family. Kiryu and the members of the Hirose Family would then chase he Jingweon into the barge and fight their way towards the spot where Joon-gi was hiding.
In the end, Kiryu confronted Han by himself to retrieve Haruto. The Jingweon leader attempted to kill Kiryu in a hand-to-hand battle, claiming that his death would be the only way for the Jingweon to move on from their past humiliation. However, Kiryu wound up the victor once more. Beaten and pressured by Kiryu, Han admitted that Tsuneo had been the one who'd hired them for the kidnapping. However, when Joon-gi started speaking about Tsuneo's pursuit to uncover the "secret of Onomichi", he was shot dead by Toru Hirose, who was hiding nearby.
After Joon-gi Han's murder, the third incarnation of the Japanese branch of the Jingweon Mafia fell apart. Many of the group's members returned to South Korea to re-join the mainland family, while several others stayed in Japan, choosing to abandon their lives of crime.
However, those former Jingweon men found that their former ties to the mafia made finding jobs and rejoining civilian life impossible. Several of these frustrated former Jingweon would then end up joining the Geomijul, an information brokerage and counterfeiting syndicate operating out of Yokohama, led by Seong-Hui, an expert forger who had once been part of the Jingweon but deserted them prior to Han's death. One of the Jingweon members who joined the Geomijul after the third incarnation's collapse was Yeonsu Kim, a man who had once worked as a body double for Han. Kim excelled as an assassin for the group and quickly gained Seong-Hui's trust, becoming her second-in-command.
In 2019, former Jingweon members who hadn't joined the Geomijul learned that Kim was still alive and using Han's name, so they tracked him down with the intent of killing him for what they perceived as disrespect of their former boss' legacy. Kim, with help from his new friend Ichiban Kasuga, managed to defeat these former Jingweon members and then persuaded them to give up fighting for the the memory of a dead organization and instead move on with their lives. With nowhere else to turn, the former Jingweon men decided to join Kim in the Geomijul.
- Jingweon Mafia Boss - Original leader of the Japanese branch (Deceased)
- Suyeon Jung - Also known as Shoko Kawara. Wife of the original Jingweon Boss (Deceased)
- Hoejong Park - Also known as Murai. One of the survivors of the Christmas Massacre, who would go on to abandon the Jingweon and their creed.
- Daejin Kim - Also known as Yukio Terada. Former bodyguard to the original boss and later 5th Chairman of Tojo Clan. (Deceased)
- Yeongmin Ji - Also known as Wataru Kurahashi. Former bodyguard to the original boss and later superintendent for the Tokyo Metropolitan Police's Foreign Affairs division. (Deceased)
- Tsumura - Hacker and bomb maker who would participate actively in Daejin Kim's plot to destroy the Tojo Clan in 2006. (Deceased)
- Jinwu Kang - Member who would undergo plastic surgery to resemble Kazuki in order to move about Kamurocho to aid Daejin Kim's revenge plan without arousing suspicion. (Deceased)
- Man in Black - Assassin who would try to kill Kazuma Kiryu multiple times in 2006. (Status Unknown)
- Joon-gi Han - New leader of the Jingweon's Japanese branch in 2016 who sought to reform the Jingweon into being more like a yakuza-style criminal organization. (Deceased)
- Seong-Hui - A professional forger who defected from the Jingweon's Japanese branch prior to Joon-gi Han's death and eventually went on to form the Geomijul.
- Yeonsu Kim - Member who underwent plastic surgery to serve as a body double for Joon-gi Han. After Han was killed and the third Japanese incarnation of the Jingweon collapsed, Kim defected to the Yokohama-based Geomijul.